Unexpected answer from Rii.
If you think that she is the youngest and shyest of berryz, but the answer is so confident.
Nice to see the changes of each personality while they grow.
And momos answer is just funny.
The image of chi hearing herself shouting "Momochi kawaii"
again and again and ...., is just priceless.
I agree that Rii did give the best, no-nonsense answer, but I think Momo showed the most "thinking outside of the box" in her reply -- the question was a thinly-disguised ploy to to get each member to identify whom she thinks is a better singer (hence Rii's delightful answer), but Momo looked at it as simply another opportunity to annoy Chii.
Also, I suspect Miya's answer was the most sentimental; graduating senpai Ai has more experience that Miya, but I would argue not more raw talent.